Process of making malleable iron castings



.Hume 17, 1924. AQBZS O. SOWERS PROCESS OF MAKING MALLEABLE IRON CASTINGS Filed July 50, 1921 252% Zaai/J7" Patented June 17, 19'24 UNITED S'TATESPATENT omer..

ossa sowens, or NEW Yoan, N. Y.

i raocnss oF MAKING'MALLEABLE moet casernes. y l

Applicatiqneld July 3Q, 19241. seriai No.' 488,514.

To all whom t may concern: l

Be it known that I, Ossa SowERs, a citizen of the United States, residing at New York, in the county of New York, and State'of 5 vNew York, have invented a new and'useful Process of Making MalleableIron Castings,

of which the following is a specification.

The principal objects of thisinvention are to shorten the time necessary for the production of malleable iron castings and, atthe same time, reduce the temperature at which they are converted and especially to permit of the manufacture of complicated and large castings of malleable iron that have had to be made without that advantage. To accomplish these objects, I use a grey iron mixture, convert a part, or all, of its surface into white iron, having free carbon, by the use of chillers, and then convert the white iron into malleable by the usual treatment, but shortened and at a lower temperature than usual. This can be done because of the fact that I have started thel process, so to speak, in the casting operation. I also prefer to use a deoxidizer to prevent cracking.

Further objects and advantages of the invention will appear hereinafter.

Reference is to be had to the accompanying drawing, which is a central vertical sectional view of a retort, shown in a mold to illustrate a preferred way of carrying out this invention.

The use of malleable cast yiron has been confined heretofore to small articles and articles of not too irregular a shape. It is well understood that malleable iron is a superior product for a great many purposes and extending its use into fields, in which it has not heretofore been possible to employ it, obviously is a valuable addition to this art. .Y

In the usual process/of producing malleable iron castings the metal is cast in a very brittle state which in itself prevents its use for many kinds of castings. After the castings are cleaned, they are subjected to an annealing process which renders the metal malleable by changing 'the condition of the carbon as is well understood. By my proc-y ess, as stated, I virtually start the conversion of the iron into malleable in the casting process. To do this, I set chillers 10 into the inside and outside of the mold over such part of the surface as desired, or usually the whole of it.4 Then I pour into the mold a mixture which, if cast inthe usualway, in sand, will produce a grey iron' casting.` Of course, the iron 1s of such .composition that,

if the ycarbon is obtainedv in acombined state, it can be malleableized. This differs from"the` known malleable 'iron foundry: practice. I use iron that normally would have its carbon inthe free-state mainly, but,

by means of the Chillers, I convert the sur. face of the metal into a condition in'whichi most or all of the carbon in the combined.

oxidizer, but will mention aluminum and titanium as being very etlicient. I also find that the presence of copper also aids in producing a better casting.

The use of the chillers differs widely, the principal determining factors being the design of the casting and the use to which the casting will be subjected in service.

In the retort illustrated, it is not necessary to make the entire casting of malleable iron, because only the lower two thirds of the casting is subj ectedto severe service.

In making a casting where the design involves difficulties in preventing the casting from cracking when cooling, only light chillers are used to form parts of the inside and outside of the mold, which will produce white cast iron in the adjacent sections of the casting, leaving an inner core of grey iron.

Although using principles 'that are well known for producing other results, I associate them in a new way, as stated, and provide a malleable iron article that will give a greater length of service, especially when subjected to high temperatures in use. I can also produce malleable 'iron castings of large size and irregular shapes that could not be made heretofore' in a practical Inanner. y Yet the malleableizing process is much shorter than has been necessary before and the heat does not have to be maintained so high. o

Although l have illustrated and described only a single embodiment of the invention, I am aware of the fact that modifications can be made therein by any person skilled in the art Without departing from' the scope of the invention as expressed in the claims. Therefore, I do not Wish to be limited to all the details of procedure herein shownand described, but what I claim is:-

l. The method of producing malleable iron castings which comprises casting an iron mixture suitable `for making grey iron, chilling its surface to convert the Surface into White iron, and subjecting it to heat to convertit into malleable iron.

iron and of a composition that, if cast in sand, Will cool in a state With ak large percentage `ofits carbon inthe free lst'ate,1chill ing the surface during casting to convert carbon Vinto thecombined state, and heating 'to inalleableiz'e the casting ata lovver temperature than that ordinarily required for malleabilizing.

3. Themetho'd of making a malleable iron article which Consists in melting an iron mixture containing a small percentage of a deoxidizing metal and suitable for producing a casting that can Lbe converted into malleable iron and of a composition that, if cast in sand, Will cool in a state with a large percentage ofits carbon in the free state, chilling the surface during casting to convert the carbon into the combined state, and heating to malleableize the casting,

In testimony whereof I have hereunto affixed my signature.

OSSA SOWERS. 

